Particularly in light armored vehicles a number of systems have been employed to rotate the turret assembly carrying a weapon through an arc and to elevate and depress the weapon in a plane substantially perpendicular to that of rotation. In other words, the weapon or weapons system is controlled both in the azimuth and the elevation so that it can be moved quickly to the target to be fired upon. Electrically actuated hydraulic systems used before have been complex and often lacking an efficient backup system in the eventuality that the electrical system failed. Particularly with regard to the elevation of the weapon, systems have been deficient in compensating for the weight of the weapon acting against other control mechanisms during weapons movement.
The invention described in detail hereinafter overcomes many of the problems of acutating systems discussed above. A feature of the invention is the simplicity and efficiency of the unique arrangement of the components which comprise the system as a whole. Also, the integration of a manual pump system with a hydraulic elevation piston-cylinder arrangement connected to a supercharger maintains proper pressure within the manual pump and avoids cavitation when the manual pump is placed in operation. An advantage of this system is the ability to maintain this supercharger at a pressure above atmosphere and to provide makeup fluid to compensate for certain operations of the hydraulic piston-cylinder arrangement for elevating and depressing the weapon.
As the piston rod displaces volume within the hydraulic elevation cylinder, during certain movements of the piston within the cylinder, more fluid will be flowing into the cylinder than will be flowing out. Consequently, it is necessary to make up this return fluid to the manual pump so that it can operate properly. This is accomplished by having the supercharger system incorporated as described.
The weapon or cannon operated by the hydraulic piston-cylinder arrangement and connected to the piston is of a substantial weight when compared to the forces in the cylinder applied to oppose gravitational forces. When the gun is lowered, the fluid in the upper portion of the cylinder will tend to be forced out under the weight of the cannon driving the piston rod upwardly. Consequently, without some control of the fluid exiting the system the cannon would typically drop faster than a desired speed for controlling movement of the weapon system to the target in an orderly manner. To compensate for this problem a one-way flow control valve is incorporated in the system to impede flow out of the elevation piston-cylinder apparatus when the weapon is being depressed. The flow control valve on the other hand operates to allow flow into the cylinder at a greater rate when the gun is being raised since the weight of the gun must be overcome by the pressure of the system to force the fluid into the cylinder.
In addition there is provided a cylinder lock valve downstream of an elevation servo-valve controlling the flow of hydraulic fluid to the elevation cylinder. The lock valve operates to lock the weapon in a position should the system become depressurized for whatever reason. The lock valve is pressure operated such that as long as there is upstream pressure the valve will remain open to allow the cylinder to be pressurized. But once this upstream pressure ceases, the lock valve will automatically close preventing any further movement of hydraulic fluid toward or away from the hydraulic elevation cylinder thus locking the piston in place.
The above has been a description of some features of the invention as distinguished from some disadvantages which had accompanied other systems of the past. The following is a more detailed discussion of the preferred embodiments from which other advantages of applicants' invention will be perceived.